The paper says Antrim born Cardinal O’Brien had a ‘long-standing physical relationship with one of the men whose complaints about his behaviour sparked his downfall as leader of the Catholic Church in Scotland’.

The report adds that the Cardinal was in a ‘long-standing physical relationship with one of the men now accusing him’.

It adds that the complainant left the priesthood in the middle of the last decade but rejoined. He is now living on the continent in a post the Cardinal helped him secure.

The paper says the priest has been in regular telephone contact with Cardinal O’Brien and was a frequent visitor to his official residence in Edinburgh.

The outspoken Cardinal, a campaigner against gay marriage, was forced to confess to the relationship after several complaints were made to the Vatican about his sexual behaviour towards priests in the 1980s.

He referred to his relationship in his resignation speech in terms of ‘sexual conduct as a priest, a bishop and a cardinal’.

The report also claims that his downfall as Britain’s leading Catholic cleric was ‘spurred by gay priests angry at his rhetoric and hypocrisy about same-sex marriages’.

The report says: “All those who complained about Cardinal O’Brien and alleged they had been abused by him were known to him for decades.

“At least two are known to have been in same-sex relationships and had become exasperated at double standards in his statements about gay marriage.

“In the six months building up to him being forced to stand down last month, the cardinal had been under some pressure from priests to tone down the rhetoric.

“However, his statements, such as describing homosexuality as a ‘moral degradation’, were a tipping point for those previously close to him.”

One of the complainants, now a Cardinal himself, was due to speak to the Herald but later declined.

A spokesman for the Catholic Church said: “The priest concerned is a priest of the diocese of Aberdeen currently on a leave of absence from parish ministry.”

One senior church figure told the paper that while some fundamentalist Catholic groups had previously linked the priest with Cardinal O’Brien ‘there were many questions that others were asking about the relationship’.

Another source said: “These guys, we now know, were part of an inner circle. In the 30 years since these allegations took place there’s been ample time to complain.

“The Cardinal has had a huge profile for the past decade. But the door wasn’t just shut on them, it was bolted in the past 18 months.

“I believe they wanted to silence O’Brien - as he’s about to do another conclave, and make a huge deal of it. As he’s retiring, a decision’s been taken to go public and take him down.”

Another told The Herald: “If you’re asking me to describe what this is about in one word, it’s revenge. I’ve no doubt the allegations did take place in the 1980s but they’ve come out to - destroy O’Brien.”

One clerical source said: “I can’t answer for those who have complained and it could well be that their reaction [to the anti-gay rhetoric] was at the heart of this. I thought his words were very harsh and I’m not alone in that. There certainly were those who were close to the Cardinal, an inner circle.

“One particular priest was a very close friend of the Cardinal. It seemed to some to be a very unusual friendship.”

A Catholic Church spokesman said: “Some clergy were not in favour of Church efforts to persuade the Scottish Government against same-sex marriage.

“It is also the case that objections were raised to Cardinal O’Brien’s robust rhetoric.

“A number of complaints about Cardinal O’Brien were passed directly to the Vatican. Whether they were precipitated by his comments on homosexuality is not known, since the detail and nature of the complaints were not shared with the Bishops’ Conference of Scotland.”